Comment by snickerbockers

Honestly even that is pretty incredible. At the very least that's enough date to count family members, possibly ID them if they have different-shaped bodies, and identify certain activities with obvious silhouettes (eg, sex).

I don't think it justifies the impending orwellian hellscape this technology will eventually unleash, but one positive thing about this that has me a bit excited is that this could easily clear up many ambiguities in criminal cases. for example, fairly often a death will get ruled as a suicide but victim's relatives and friends will insist that it must have been a murder; imagine being able to use this technology to definitively prove whether or not there was another party present when the victim died.

Or in rape cases where the defendant is protesting their innocence, knowing the body language of the victim and the defendant could be a vital clue because you might be able to observe the victim fighting back.

Again, I don't think the positives outweigh the negatives to the point that it could ever justify an invasion of privacy on this scale (you might as well just make everybody let the government set up a thermal camera in their house!) but it is interesting to think about the problems this could solve.